Modular chemistry analyzer

ABSTRACT

A chemistry analyzer is disclosed that can include a unitary base with vertical and horizontal supports for constraining subassemblies. The subassemblies include at least a reagent/sample carousel subassembly, a transfer arm subassembly, and a reaction carousel subassembly. A centralized hydraulic system can also be provided behind a user access panel. The analyzer can use machine-readable test specifications coupled with its reagent vessels to define tests that include operations that employ the reagents. The analyzer can also display to the operator a pictorial representation that includes graphical elements that convey levels of usage for the storage vessels, and access icons that are each associated with a color and each lead to a set of screens for different types of operations for the analyzer.

FIELD OF THE INVENTION

This invention pertains to chemistry analyzers for use in clinicalsettings.

BACKGROUND OF THE INVENTION

Chemistry analyzers are very important health care tools. They candetect imbalances in a number of chemical species in bodily fluids, suchas cholesterol, glucose, enzymes, iron, magnesium, protein, uric acid,chlorine, lithium, potassium, or sodium. This information can help todiagnose a variety of conditions, such as high cholesterol, abnormalliver function, or diabetes, to name only a few. Improvements to thequality of measurements performed by chemistry analyzers could thereforehave a positive effect on the care of a very large number of patients.

A chemistry analyzer is also a relatively expensive item for a healthcare provider, such as a hospital, and this cost is usually passed on tohealth care consumers. The cost that is passed on can be affected by theinitial cost of the analyzer, the cost of reagents and reactioncuvettes, and the cost of maintaining and servicing the analyzer.Improvements that lead to a reduction in cost of chemistry analyzers andtheir maintenance could therefore have a positive effect on the overallcost of health care. And the overall health care savings resulting fromeven a relatively small reduction in the costs associated with ananalyzer could be substantial in view of the large number of patientsserved by these analyzers.

The cost savings could also help make the technology available to morepatients. In developing countries and remote or less affluent regions ofdeveloped countries, cost may prevent health care providers from havingeasy access to a chemistry analyzer. They might thus need to sendsamples to remote facilities, recommend that patients travel to thosefacilities, or even diagnose conditions without the benefits ofautomated chemical analysis. Improvements that lead to a reduced cost ofchemistry analyzers and their maintenance could therefore have asignificant effect on the availability of health care as well as thepromptness and efficiency with which it can be delivered.

One common chemistry analyzer design employs two carousels and atransfer arm equipped with a probe. The first carousel carries patientsamples and reagents, which can be cooled to maintain stability. Thetransfer arm and probe move small amounts of reagents and samples to oneof a series of reaction cuvettes carried by a second, heated carousel.The reaction mixture can then be subjected to photometric tests ortransferred to a module containing sensors for potentiometric analysis.A fluidic system provides fluid for sample dilution and for washing theprobe and fluid lines, and an electrical system relays results andprovides power and sequencing signals to the various parts of theanalyzer. Other designs of chemistry analyzers utilize two or moretransfer arms and probes, and two or more carousels for samples andreagents.

In existing chemistry analyzers, various parts of the analyzer aretypically mounted to a metal chassis. Wires, cables, and supply andwaste tubes are connected between the mounted parts, and covers surroundand protect the assembled analyzer.

SUMMARY OF THE INVENTION

In one general aspect, the invention features a chemistry analyzer thatincludes a unitary base, for mounting a plurality of subassemblies thatinclude at least a reagent/sample carousel subassembly, a transfer armsubassembly, and a reaction carousel subassembly. The base has verticalsupports including at least one support for each subassembly, with eachvertical support constraining its subassembly in the horizontaldirection. It also has horizontal supports including at least threesupports for each subassembly, with each horizontal support constrainingits subassembly in the vertical direction.

In preferred embodiments, the horizontal supports can be each defined bya single boss. A plurality of the horizontal supports for at least oneof the subassemblies can be provided by a single support surface. Thevertical supports can be each defined by a single pin. The base caninclude two vertical supports for at least one of the subassemblies toconstrain rotation of that subassembly. The base portions can include atleast a paired boss and pin for each of the subassemblies, with thepaired boss being positioned to protrude above the paired pin. At leasttwo pins can define vertical supports for the reagent/sample carouselsubassembly, at least two pins can define vertical supports for thereaction area subassembly, and at least one pin can define the verticalsupport for the transfer arm subassembly. The base can comprise a singlemolded base part with the horizontal supports being machined horizontalareas of the single molded base part. The analyzer can further includeat least a further vertical support and a further horizontal support fora wash station subassembly. The analyzer can further include at least afurther vertical support and a further horizontal support for aphotometer subassembly. The horizontal and vertical supports can fullyconstrain each of the subassemblies independent of any fasteningmechanism.

In another general aspect, the invention features a method for achemistry analyzer that includes horizontally constraining each of aplurality of chemistry analyzer subassemblies with horizontal supportsdefined by an integral base, and vertically constraining each of theplurality of chemistry analyzer subassemblies with at least one verticalsupport defined by the integral base.

In a further general aspect, the invention features an integral basemeans that define a plurality of horizontal chemistry analyzersubassembly constraining means for each of a plurality of chemistryanalyzer subassemblies, and at least one vertical chemistry analyzersubassembly constraining means for each of the plurality of chemistryanalyzer subassemblies.

In another general aspect, the invention features a chemistry analyzerthat includes a chassis for mounting a plurality of chemistry analysissub-assemblies, a housing surrounding the chemistry analysissub-assemblies, a user access panel on the housing, and a centralizedhydraulic system area defined to house a plurality of hydraulic elementsoperative to handle fluid for the plurality of subassemblies in theanalyzer. These hydraulic elements are located in the housing and behindthe user access panel.

In preferred embodiments, the hydraulic system can include consumablehoses that are replaceable through the access panel. The system caninclude circuitry that permits the system to operate while the accesspanel is open. The chemistry analyzer can further include a drawer basethat defines the centralized hydraulic system area, with the user accesspanel being a drawer front mounted on the drawer base.

In a further general aspect, the invention features an automatedchemistry analysis method that includes receiving a modular chemistryanalysis test unit that includes one or more vessels for one or morereagents, and a machine-readable test specification coupled with thevessels and defining a test that defines a test including a series ofoperations that employ the reagents for the vessels. The method alsoincludes installing the chemistry analysis test unit in a firstchemistry analyzer that includes one or more analysis tools andsequencing logic for sequencing instructions to be carried out by theanalysis tools, and automatically retrieving the machine-readable testspecification from the chemistry analysis test module and storing it foraccess by the sequencing logic to allow the sequencing logic to instructthe analysis tools to carry out the test defined by the testspecification.

In preferred embodiments, the step of automatically retrieving canoperate independent of any software upgrade for the analyzer. Themachine-readable test specification can be stored in an RFID tag affixedto the vessel. The vessel is a compound multi-reagent vessel that caninclude subvessels for a plurality of reagents, with themachine-readable test specification including information definingoperations using the plurality of reagents stored in the subvessels. Thestep of receiving can receive a modular chemistry analysis test unitthat further includes one or more machine-readable reagent quantityvalues, and can further include the step of storing an updated versionof the machine-readable reagent quantity values after use by the firstchemistry analyzer of one or more reagents from the modular chemistryanalysis test unit. The method can further include the step ofinstalling the chemistry analysis test unit in a second chemistryanalyzer that includes one or more analysis tools and sequencing logicfor sequencing instructions to be carried out by the analysis tools, thestep of automatically retrieving the machine-readable test specificationfrom the chemistry analysis test module and storing it for access by thesequencing logic to allow the sequencing logic to instruct the analysistools to carry out the test defined by the test specification, and thestep of storing an updated version of the machine-readable reagentquantity values after use by the second chemistry analyzer of one ormore reagents from the modular chemistry analysis test unit. The methodcan further include the step of installing the chemistry analysis testunit in a second chemistry analyzer that includes one or more analysistools and sequencing logic for sequencing instructions to be carried outby the analysis tools, and the step of automatically retrieving themachine-readable test specification from the chemistry analysis testmodule and storing it for access by the sequencing logic of the secondchemistry analyzer to allow the sequencing logic to instruct theanalysis tools to carry out the test defined by the test specification.

In another general aspect, the invention features a modular chemistryanalysis test unit for a chemistry analyzer that includes one or morevessels for one or more reagents, and a machine-readable testspecification coupled with the vessels and identifying a series of testoperations that employ the reagents for the vessels The specificationincludes one or more reagent quantity specifications that specify aquantity of the reagents to mix with a test sample, and one or morereaction duration specifications that specify a reaction time for thereagents and test sample.

In preferred embodiments, the machine-readable test specification can bestored in an RFID tag affixed to the vessel. The machine readable testspecification can further include at least one test type specificationdefining a type of test to be performed. The machine readable testspecification can further include at least one result valuespecification defining an acceptable result value for a test to beperformed using one or more of the reagents. The test unit can furtherinclude a machine-readable storage area for a fill level value. Themachine-readable storage area for a fill level value can be a read-writestorage area. The machine-readable tag can be affixed to one or more ofthe vessels with an adhesive.

In a further general aspect, the invention features a machine-readableidentification tag for chemistry analysis test units for use in achemistry analyzer that includes a machine-readable test specificationdefining a series of test instructions for access by sequencing logic,which include one or more reagent quantity specifications that specify aquantity of reagent to mix with a test sample, and one or more reactionduration specifications that specify a reaction time for the reagent andtest sample.

In preferred embodiments, the tag is can be an RFID tag. The machinereadable test specification can further include at least one test typespecification defining a type of test to be performed. The machinereadable test specification can further include at least one resultvalue specification defining an acceptable result value for a test to beperformed according to the reagent quantity specification and thereaction duration specifications. The tag can further include amachine-readable storage area for a fill level value. Themachine-readable storage area for a fill level value can be a read-writestorage area. The tag can further include an adhesive area to affix thetag to a portion of the chemistry analysis test unit.

In another general aspect, the invention features a method of operatinga chemistry analyzer method that includes determining usage levelsassociated with a plurality of storage vessels that store reagents foruse by the analyzer, displaying to the operator a pictorialrepresentation that includes a plurality of graphical elements thatconvey levels of usage for the storage vessels, and displaying a seriesof access icons that are each associated with a color and each lead to aset of screens for different types of operations for the analyzer,wherein the screens are color coded to correspond to the colorassociated with their respective access icons.

In preferred embodiments, the method can further include the step ofidentifying the contents of a plurality of storage vessels that storesamples for use by the analyzer, and the step of displaying to theoperator a pictorial representation that includes a plurality ofelements that identify the contents of the storage vessels. Thepictorial representation of the reagent vessels and the sample vesselscan be part of a combined representation. The pictorial representationcan be a mapped pictorial representation in which positions of thegraphical elements on the display correspond to positions of the vesselsin the analyzer. The pictorial representation can employ a colored barto convey usage levels. The pictorial representation can includeelements that identify the reagents in the storage vessels. The step ofdisplaying access icons can display icons that include at least aworklist icon and a results icon. The step of displaying access iconscan display icons that include at least a worklist icon and a statusicon. The step of displaying access icons can display icons that includeat least a results icon and a status icon. The step of displaying accessicons can display icons that include a worklist icon and a diagnostics,maintenance, and/or setup icon. The step of displaying access icons candisplay icons that include a results icon and a diagnostics,maintenance, and/or setup icon. The step of displaying access icons candisplay icons that include a status icon and a diagnostics, maintenance,and/or setup icon. The step of displaying access icons can display iconsthat include a status icon and a diagnostics, maintenance, and/or setupicon. The step of displaying access icons can display icons that includea worklist icon, a status icon, and a diagnostics, maintenance, and/orsetup icon. The step of displaying access icons can display icons thatinclude a worklist icon, a results icon, and a diagnostics, maintenance,and/or setup icon. The step of displaying access icons can display iconsthat include a results icon, a status icon, and a diagnostics,maintenance, and/or setup icon. The step of displaying access icons candisplay icons that include a worklist icon, a results icon, and a statusicon. The step of displaying access icons can display icons that includea worklist icon, a results icon, a status icon, and a diagnostics,maintenance, and/or setup icon.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an illustrative modular chemistryanalyzer according to the invention;

FIG. 2 is a perspective view of the chemistry analyzer of FIG. 1 showingfluidics components and covers for operator use in phantom;

FIG. 3 is a perspective view of the chemistry analyzer of FIG. 1 withits inner cover removed to reveal functional subassemblies as accessedby service personnel;

FIG. 4 is a plan view of a base for use in the chemistry analyzer ofFIG. 1;

FIG. 5A is a cross-sectional view of a boss-pin pair for the base ofFIG. 4;

FIG. 5B is a cross-sectional view of a another type of boss-pin pair forthe base of FIG. 4;

FIG. 5C is a cross-sectional view of a further type of boss-pin pair forthe base of FIG. 4;

FIG. 6 is a front isometric view of the base of FIG. 4;

FIG. 7 is a rear isometric view of the base of FIG. 4;

FIG. 8 is an exploded assembly drawing showing the bottom of the base ofFIG. 4 and its stiffening plate;

FIG. 9 is a rear perspective view of the chemistry analyzer of FIG. 1with its electronics subassembly shown in its open position;

FIG. 10 is a partial perspective view of the illustrative modularchemistry analyzer of FIG. 1, showing the installation of an optionalcooling unit fan in the reagent/sample area;

FIG. 11 is a partial perspective view of the illustrative modularchemistry analyzer of FIG. 1, showing the installation of its powersupplies behind the reagent/sample area;

FIG. 12 is a rear-facing partial perspective view of the illustrativemodular chemistry analyzer of FIG. 1, showing the installation of itselectronics subassembly;

FIG. 13 is a partial perspective view of the illustrative modularchemistry analyzer of FIG. 1, showing the installation of itsreagent/sample carousel subassembly;

FIG. 14 is a partial perspective view of the illustrative modularchemistry analyzer of FIG. 1, showing the installation of its heater;

FIG. 15 is a partial perspective view of the illustrative modularchemistry analyzer of FIG. 1, showing the installation of its reactionarea carousel drive subassembly;

FIG. 16 is a partial perspective view of the illustrative modularchemistry analyzer of FIG. 1, showing the installation of its cuvettecarousel and air filter above the reaction area carousel drivesubassembly;

FIG. 17 is a partial perspective view of the illustrative modularchemistry analyzer of FIG. 1, showing the installation of its transferarm subsystem;

FIG. 18 is a partial perspective view of the illustrative modularchemistry analyzer of FIG. 1, showing the installation of its fluidicssubsystem drawer base;

FIG. 19 is a partial perspective view of the illustrative modularchemistry analyzer of FIG. 1, showing the installation of its fluidicssubsystem drawer front;

FIG. 20 is a partial perspective view of the illustrative modularchemistry analyzer of FIG. 1, showing the installation of itsphotometer.

FIG. 21 is a perspective view of an illustrative two-part reagentcontainer for use with the chemistry analyzer of FIG. 1;

FIG. 22 is an illustrative memory map for the illustrative reagentcontainer for use with the chemistry analyzer of FIG. 1;

FIG. 23 is a flowchart illustrating the operation of the chemistryanalyzer of FIG. 1; and

FIG. 24 is a screenshot of a worklist screen for the chemistry analyzerof FIG. 1.

DESCRIPTION OF AN ILLUSTRATIVE EMBODIMENT

Referring to FIGS. 1-2, an illustrative embodiment of a modularchemistry analyzer 10 according to the invention includes areagent/sample area 12, a transfer arm/probe 14, a reaction area 16, afluidics drawer 18, and a diluent/waste bottle area 20. The analyzer isalso equipped with a computer 24 and a touch screen 22.

Referring to FIGS. 2-3, a first pivoting cover 30 encloses areagent/sample carousel subassembly 50 in the reagent/sample area, and asecond pivoting cover 32 encloses a reaction carousel subassembly 70 inthe reaction area. A transparent pivoting fluidics drawer front 34protects a fluidics area 40 mounted on a sliding drawer base 36. Thefluidics area can include an optional module that includes a series ofIon-Selective Electrode (ISE) sensors 42 and peristaltic pumps 48. Thefluidics area also includes a diluter pump 46. Mounted to the ISE sensormodule is a probe wash cup 44.

Referring to FIG. 3, the reagent/sample carousel subassembly 50 includesa reagent tray 52 supported by a carousel drive subassembly 56 that isabove an optional cooling unit 58, such as a Pelletier cooling moduleand its associated cooling fan 57 (see also FIGS. 10 and 13). It alsoincludes a removable sample ring 54 that holds sample containers 60 andis loaded on top of the reagent tray, after it is loaded with reagentcontainers 62 during the ordinary course of operation (see also FIG.21). A Radio Frequency Identification (RFID) reader 68 can be located inthe analyzer's base adjacent the carousel drive subassembly, as well, tointeract with RFID tags associated with the reagent containers. Anoptional bar code reader that is mounted on the base adjacent to thesample ring can read bar codes on the sample containers.

The reaction carousel subassembly 70 includes a cuvette wheel 72 mountedon a reaction carousel drive subassembly 74 adjacent a photometer 76 andabove a heater 80. The transfer arm/probe 14 is part of a transferarm/probe subassembly 82 that is positioned off-axis between the twocarousels. Power supplies 84 are mounted behind the transfer arm, and anelectronics subassembly 86 is mounted in a case 38 at the back of theanalyzer (see also FIG. 12).

Referring to FIGS. 4-7, a unitary base 90 supports the analyzer'ssubassemblies in a predetermined way. The base employs supports, such aspins 94 and bosses 96 to precisely and accurately position thesubassemblies (e.g., the sample/reagent subassembly). The pins aredesigned to interact with holes in the subassemblies to constrain themat predetermined horizontal positions (i.e., in the x- andy-directions). The bosses are designed to position the subassemblies atpredetermined heights (i.e., in the z direction). The unitary moldedbase and pins and bosses minimize stack-up between the elements andgreatly reduce the manufacturing and assembly costs of this embodiment.

The pins 94 and bosses 96 can be provided in different types of pairs 92as shown in FIGS. 5A-5C, but they can also be placed at separatelocations. A pin and boss may be paired to provide horizontal constraintas well as vertical constraint, as illustrated in FIG. 5C.

A support is a part or portion of a part, such as the base, thatprovides an opposing force to a point on a subassembly. The minimumnumber of supports required is defined by the number of degrees offreedom that need to be constrained. An object that is otherwiseunconstrained, for example, would require at least two verticalsupports, such as two pins, and three horizontal supports, such as threebosses. One pin would prevent horizontal translations, but not rotation,and a second pin would fully constrain a subassembly in the x-y plane.And, like a stool generally requires at least three legs, three pointbosses are used to support an otherwise unconstrained subassembly in thez-direction.

Some subassemblies may only need to be partially constrained, or may notneed to be constrained at all. The analyzer's power supplies, forexample do not need to be constrained precisely, so there is no need toprovide pins and bosses for them. Other subassemblies could beconstrained precisely in one or more directions, but not in one or moreothers. And while cost dictates that it is generally preferable to use aminimum number of pins and bosses to achieve a set of targetconstraints, additional pins and bosses could also be used in somecircumstances, such as to support a large or flexible subassembly. Insome situations it may even be possible to provide one precisely shapedlarger surface to define two or more supports at different positions.Other types of precisely dimensioned vertical constraints could also beprovided, such as irregularly shaped pins or precisely dimensionedblades, teeth, or walls.

Screws can secure the constrained subassemblies in place but are notappropriate for aligning the subassemblies. This is because screws needroom to move within their holes, they are typically not manufacturedwith a high degree of precision, and they may be replaced in the fieldwith similar-looking but differently dimensioned screws. The act ofinstalling screws can sometimes also damage their through holes,especially if the subassembly is not precisely positioned beforeinstallation begins. The screws therefore only serve to secure thesubassemblies and can cooperate with tapped inserts 98, which can belocated in the bosses. Other types of fastening arrangements could alsobe employed, such as cams, clamps, or barbs. The pins and horizontalsupports used for the base in one embodiment are listed in table 1.

Subassembly Description Transfer arm Single pin lines up with axis ofrotation of transfer arm, and minimum of three horizontal supports.Reaction carousel Minimum of two pins and three horizontal supportsReagent/sample Minimum of two pins and three horizontal supportscarousel

The use of pins, bosses, and other ways of providing supports can allowfor easy assembly and very high precision positioning of subassemblies,at a relatively low cost. In one embodiment suitable for prototyping orsmall runs, for example, the base is first molded in a conventionalmanner, such as using a conventional cast urethane process. Holes forthe pins and the upper boss surfaces are then precisely machined using anumerical milling machine. While the precision machining can add somecost to the base, this cost amounts to a relatively small portion of theoverall cost of the analyzer, and it is offset by several benefits. Inanother embodiment suitable for larger runs, adequate tolerances havebeen achieved, without machining, using Noryl, a Polyphenylene Oxide(PPO) engineering thermoplastic available from General Electric.

A first benefit of the base construction is that it makes the analyzereasy to assemble and service. Assembly technicians and field servicetechnicians can quickly position a subassembly by first aligning holesin the assembly with the pins that constrain it and then dropping thesubassembly into place. Getting the pins and holes to line up is anoperation that has is very definite feel to it, so the technicianimmediately knows the part is properly engaged. And once engaged, thesubassembly is perfectly positioned, so there is no need to adjust itsposition during assembly. The analyzer can also be built to be assembledand disassembled with a single tool, such a number two Phillipsscrewdriver.

Simplifying assembly can also reduce the length and complexity ofservice and subassembly replacement tasks, and thereby allow them to beperformed by less skilled personnel, such as sales representatives oreven hospital staff. This can significantly reduce the cost of thesetasks, particularly in remote areas. And simplifying service tasks canreduce the complexity of service manuals, which can then be more easilytranslated.

Another benefit of the unitary base construction is that it can reduceor eliminate the need for calibration of the transfer arm. With thesubassemblies positioned precisely relative to each other, the transferarm may be able to employ a preset travel range. It therefore need notgo through an initial calibration routine or be “taught” by a technicianwhere its different landing points are. If a calibration step is stillneeded, this step may be designed to take less time than might otherwisebe required.

The molded base 90 is designed to eliminate tolerance stack-up in thisembodiment. This can be achieved by carefully designing the order andreference points for distance measurements used in cutting the basemold. Basing measurements from the transfer arm axis pin T1 to pins thatconstrain the probe's service points, for example, will avoid theaccumulation of tolerances that could result if the position of all ofthese pins were to be based on an arbitrary reference. This contrastswith the difficulties and expense that appears to have been required inprior art designs to control tolerance stack-up between probe, reagentcontainers, sample containers, reaction cuvettes, probe wash station,and other elements. The use of plastic in the base also reduces thermalexpansion errors in this embodiment.

Referring to FIG. 8, to maintain precise positional tolerances, the baseis also preferably reinforced, such as with webbing 88 and a stiffeningplate 89. The use of a stiffening plate is an alternative to thickwebbing, and it therefore reduces the overall height of the analyzer.The reinforced base is also solidly bolted to a rear portion thatdefines the electronics subsystem case 38, as shown in FIG. 9, to makeit even stiffer.

Referring to FIG. 10, assembly of the analyzer includes the installationof the fan 57 for the optional cooling unit 58 in the sample/reagentarea 12. This fan is held down with screws, but does not require pins orbosses.

Referring to FIG. 11, the power supplies are inserted into an areabehind the sample/reagent area. This location makes them relatively easyto replace. As discussed above, the power supplies do not requireprecise positioning, so no pins or bosses are provided for them. Thepower supply is connected to the various components that it supplies viaa series of cables, which are preferably equipped with connectors, suchas plug and socket connectors, to simplify assembly, disassembly, andservicing.

Referring to FIG. 12, the electronics subassembly 86 is made up of amother board and daughter cards. The mother board is screwed to a hingedcover 87 for the case 38 at the back of the analyzer. In this highlyaccessible position, it is easy to diagnose failures, and/or repair orreplace the assembly, its daughter cards, or other components.

The purpose of the electronic subassembly 86 is to control the operationof the analyzer and relay results to the operator. It is thereforeelectrically connected to various parts of the analyzer via a number ofwires and/or cables. These are preferably equipped with connectors, suchas plug-and-socket connectors, to simplify assembly, disassembly, andservicing.

Referring to FIG. 13, the reagent/sample tray drive and coolingsubassembly 56 is screwed in place above the cooling unit fan 57 in thesample/reagent area 12 of the analyzer. As presented earlier, thissubassembly is precisely positioned within the transfer arm's rangeusing two pins and three bosses.

Referring to FIG. 14, the heater 80 is held in place in the reactionarea by screwing it to two posts that are integral to the base 90. Theseheight of these posts need not be precisely defined as the heater doesnot need to be positioned with a high degree of precision.

Referring to FIG. 15, the reaction area carousel drive subassembly 74 isscrewed in place on three posts. These posts are precisely defined, suchthat some or all of their top surfaces can act as bosses, and two ofthem include pins. An air filter 78 is installed above the drivemechanism, and the cuvette wheel 72 can then be screwed to the reactionarea carousel drive mechanism above the air filter, as shown in FIG. 16.The wheel holds disposable transparent reaction cuvettes ganged ingroups of six.

Referring to FIG. 17, the transfer arm subassembly 82 is screwed onto aseries of three bosses and constrained by two pins, with one of the pinsbeing placed directly below the axis of rotation of the transfer arm.This precise positioning keeps the transfer arm and post at an exactrelative position with respect to the various points that it needs toservice, including one or more openings in the reagent and samplecontainers on the reagent/sample carousel, cuvettes on the cuvettecarousel, the wash cup, and a sample cup on the ISE sensor module.

Referring to FIG. 18, the fluidics drawer base 36 is attached to the topof the base 90 of the unit with four screws. It is also constrained bybosses and pins to keep its ISE sensor module 42 and probe wash cup 44precisely positioned within the transfer arm's range. One of themounting screws is grounded.

Referring to FIG. 19, the transparent pivoting fluidics drawer front 34is pivotably mounted on the drawer base 36 using a pair of brackets andfour screws. This component does not need to be constrained with a highdegree of precision, since its only purpose is to act as a cover.

The use of a sliding fluidics drawer makes the fluidics subassembly easyto access and troubleshoot. Bubbles and blocked lines are clearlyvisible through the transparent cover 34 or with the drawer open, andsome fluidics items may even be repaired or replaced without removingthe analyzer's covers.

Referring to FIG. 20, the photometer 76 is mounted on a pedestal 94 thatis integral to the base at the rear of the reaction area. It issupported by two rear bosses and one front boss. A screw interfaces witha tapped insert between the two rear bosses to hold the photometer toits pedestal. This arrangement is sufficient to position the photometerwith respect to the cuvette carousel and thereby allow it to takephotometric measurements through the transparent cuvettes.

The assembly tasks described above cover the bulk of the assembly of theillustrative chemistry analyzer 10. One of ordinary skill in the artwould of course recognize that there are a variety of smaller assemblysteps, such as the attachment of covers and the installation of cables,hoses, and other small parts. But these details do not bear on theinvention and have been omitted in the interest of clarity.

In operation, referring to FIGS. 1-3, the user begins by loading one ormore reagent containers 62 in the reagent tray 52 and one or moredisposable cuvettes in the cuvette wheel 72. The user also installs thesample ring 54 and any sample containers 60 that contain samples foranalysis. After closing the reagent carousel cover, the analyzerperforms a reagent inventory and/or a sample inventory (see FIG. 23 andaccompanying text). The analyzer is now ready to carry out analysistasks for the different samples using one or more reagents from one ormore containers in the reagent tray.

Referring to FIGS. 21-22, all of the information required to carry outthe analysis sequence for each the reagents is contained in an RFID tag64 under the label 66 of its reagent container 62. As shown in FIG. 22,this information can include: name, lot number, and expiration date,reagent volumes(s), reagent and sample blanking, analysis volumes forreagents, samples, and diluent, linear range of assay, primary andsecondary wavelengths for photometric measurements, acceptableabsorbance ranges, reaction read times, and urine parameters.

Storing all of this protocol information in the RFID tags in the reagentcontainers themselves can help to ensure that no test is ever conductedwith an incorrect protocol. And there is no need to update theanalyzer's software periodically to ensure that it is compatible withnew tests. Instead, all of the information needed to run new tests andimprovements to old tests can be simply read from the RFID tags on thereagent containers in the reagent tray, and the analyzer will use themcorrectly.

Storing the analysis protocol in the RFID tags on the reagent containersalso has the advantage of allowing the container manufacturer to tailorthe protocol for different reagent batches. If the manufacturer receivesa reagent with a very slightly lower concentration than it specified,for example, reaction times can be slightly altered to correct for thisdiscrepancy without any impact on precision or accuracy. This level offlexibility can even reduce the cost of producing reagents by relaxingthe required tolerances for reagents. And it can increase thesensitivity of tests even if the reagents are within conventional,narrow ranges, by setting reaction parameters exactly for each batchinstead of at a target nominal value that is good for all batches.

The RFID tags in the reagent containers can also store informationreceived from the analyzer during operation, such as updated reagentvolumes. Storing this information in the reagent containers can allowthem to be moved from one analyzer to another or even allow them tosurvive computer failures without loss of reagent volume information.This can help to avoid a potentially serious situation in which noreagent of a particular type is on hand because the amount of reagent inexisting containers was not known correctly.

Referring to FIG. 23, upon startup or user request, the analyzerinitiates a reagent inventory operation in which the reagent tray isrotated to expose each of the reagent containers to the RFID reader 68(step 100). The analyzer first retrieves the contents of a first tag(step 102). It can then check it to determine whether it holds a newprotocol (step 104), and store it if it does (step 106). The testprotocols can be stored in storage located in the analyzer housing, instorage located in the computer, or in another location, such as acentral networked server. The inventory process is repeated for all ofthe reagent containers in the system (see step 108).

Once the protocols are stored, the system is ready to select andinitiate analysis tasks (step 110). Each test begins with the analyzeraccessing the stored test protocol corresponding to the reagentcontainer to be used (step 112). The various subsystems then carry outthe sequence of events in the test protocol (step 114). A sample andreagent might be mixed in a cuvette, for example, and the result testedusing the photometer after a specified reaction read time. The testresult is then stored (step 116), and further tests can be conducted forfurther samples (step 118).

The flowchart shown in FIG. 23 is illustrative only, and the inventoryand test operations can take place according to other sequences. It maymake sense in some instances to simply record all protocol data for allreagent containers, for example, even if data for some or all of them isredundant. Analysis tasks may also be interleaved to save time.

Inventory initiation can be made mandatory each time that reagentsand/or samples could be removed from the system. For example, theinventory can be initiated each time the cover 30 for the reagent/samplecarousel subassembly is closed. This interlock mechanism can preventerrors by ensuring that regent or sample containers are not replaced,moved, or removed before testing begins.

Referring to FIG. 24, the operator can interact with the analyzer 10through a series of software-generated views presented on the touchscreen 22. The worklist screen 200, for example, includes one or morestatus icons 202, an icon bar 204, a visual representation 206 of halfof the reagent tray 52/sample ring 54, and a data table 208. The visualrepresentation shows what reagent containers are in the reagent traybased on the results of an earlier inventory, by displaying a series ofwedge shapes that are similar to the shape of the reagent containers. Italso shows occupied positions in the sample ring as white numberedcircles and unoccupied positions in shaded circles positioned in asemicircular area that is similar to the sample ring. The quantity ofreagent left in each reagent container is shown as a shaded area thatresembles a fill level in the wedge shape, and the reagent containersare identified by standard abbreviations (e.g., Ca for calcium). Thedata table shows a list of tests that correspond to the different sampleareas, which are referenced by their numbers in the visualrepresentation. Together, the elements of the worklist screen allow theuser to quickly understand the status of the system and the run of teststhat is about to begin.

The icon bar 204 includes four differently colored icons that divide theoperation of the system into four functional areas. Touching these iconsleads the user to menus allowing him or her to select from a series ofsub-screens in each of these areas. Each of the sub-screens is colorcoded to remind the user what type of task he or she is performing.

This approach of using a combination of color coding and visualrepresentations helps orient the user and avoid errors. This can beparticularly helpful for users for whom the language used by theanalyzer is a second language. It also allows the analyzer to use textmore sparsely, which is beneficial for models deployed in a variety ofdifferent markets, as the user interface can be designed with little orno text that needs to be translated.

In one embodiment, the four icons include a woorklist icon 210 (blue), aresults icon 212 (orange), a status icon 214 (green), and adiagnostics/maintenance/setup icon 216 (pink). The worklist groupaccessible from the worklist icon 210 includes a view LIS list entry, anedit worklist entry, a monitor worklist entry, a view pending listentry, and an ISE calibration entry. The results group accessible fromthe results icon 212 includes a current results entry, a last resultsentry, a patient results entry, calibration results entry, a qualitycontrol results entry, and an other tables entry. The status groupaccessible from the status icon 214 includes a worklist warnings entry,a reagents entry, a calibration entry, a quality control entry, acuvettes entry, an ISE entry, a cleaning entry, an inventory reportentry, and a sample inventory entry. The diagnostics/maintenance/setupgroup accessible from the diagnostics/maintenance/setup icon 216includes a cleaning entry, a diagnostics entry, a maintenance entry, anda setup entry. The setup entry includes sub-entries for system, tests,patient, calibration, quality control, and reagent. One of ordinaryskill in the art will recognize that the exact breakdown of the screensis highly dependent on the detailed characteristics of the particularchemistry analyzer, and that there are a variety of different,reasonable ways to organize the screens for a given analyzer.

The various tasks performed by the analyzer can be carried using aspecially programmed general purpose computer, dedicated hardware, or acombination of both. In one embodiment, the system is based on aMicrosoft Windows®-based computer system, but other platforms could beused as well, such as Apple McIntosh®, Linux®, or UNIX®-based platforms.And while the touch screen is a currently a preferred user interfacedevice, other types of devices could also be used, such as mice,keyboards, or trackballs. Other embodiments can even employ a simple,hardwired keypad instead of a computer.

The present invention has now been described in connection with a numberof specific embodiments thereof. However, numerous modifications whichare contemplated as falling within the scope of the present inventionshould now be apparent to those skilled in the art. It is thereforeintended that the scope of the present invention be limited only by thescope of the claims appended hereto. In addition, the order ofpresentation of the claims should not be construed to limit the scope ofany particular term in the claims.

What is claimed is: 1-56. (canceled)
 57. A method of operating achemistry analyzer that includes: a processor and a storage deviceincluding instructions configured to run on the processor, areagent/sample carousel subassembly for holding a plurality of reagentvessels and sample vials for holding samples of different patients, aplurality of different reagent vessels that each store one or moredifferent reagents for testing different selected analytes and aplurality of sample vials for holding patient samples, a reactioncarousel subassembly that defines cuvette locations, a transfer armsubassembly including a probe for transferring reagents and samples tothe cuvette locations, a probe wash station positioned along an arc ofmotion of the transfer arm, a photometer positioned to acquirephotometric measurements from the cuvette locations in the reactioncarousel, and a touch screen, wherein the touch screen is operativelyconnected to the processor, comprising: simultaneously displaying on thetouch screen a display area and a series of four access icons includinga worklist icon, a results icon, a status icon, and a diagnostics,maintenance, and/or set up icon, which are each associated with adifferent color and each allow access to information for different typesof operations for the analyzer, wherein the information is color codedto correspond to the color associated with their respective accessicons, displaying a worklist menu in response to user actuation on thetouch screen of the worklist icon that is associated with a first color,while continuing to display the four access icons on the touch screen,displaying in response to a user selection in the worklist menu one of aplurality of sub-screens that is color coded according to the firstcolor in the display area, including a data table sub-screen that liststests for the analyzer, while continuing to display the four accessicons on the touch screen, displaying a status menu in response to useractuation on the touch screen of the status icon that is associated witha second color, while continuing to display the four access icons on thetouch screen, displaying in response to a user selection in the statusmenu one of a plurality of sub-screens that is color coded according tothe second color in the display area, including a status sub-screen thatlists a plurality of status entries for the analyzer, while continuingto display the four access icons on the touch screen, displaying aresults menu in response to user actuation on the touch screen of theresults icon that is associated with a third color, while continuing todisplay the four access icons on the touch screen, displaying inresponse to a user selection in the results menu one of a plurality ofsub-screens that is color coded according to the third color in thedisplay area, including a results sub-screen that lists a plurality ofresults entries for the analyzer, while continuing to display the fouraccess icons on the touch screen, displaying a diagnostics, maintenance,and/or setup menu in response to user actuation on the touch screen ofthe diagnostics, maintenance, and/or setup icon that is associated witha fourth color, while continuing to display the four access icons on thetouch screen, displaying in response to a user selection in thediagnostics, maintenance, and/or setup menu one of a plurality ofsub-screens that is color coded according to the fourth color in thedisplay area, including a diagnostics, maintenance, and/or setup iconentry sub-subscreen for the analyzer, while continuing to display thefour access icons on the touch screen.
 58. The method of claim 57further including the steps of: determining reagent fill levelsassociated with the plurality of reagent vessels that store the reagentsfor use by the analyzer, displaying to the operator a pictorialrepresentation that includes a plurality of graphical elements thatconvey the fill levels for the reagent vessels, wherein each graphicalelement corresponds to one of the reagent vessels, and wherein the filllevels of the reagent vessels are each represented by one of a pluralityof different visual fill level representations that each resemble adifferent fill level in a corresponding graphical element, transferringreagents from the reagent vessels to one or more reaction vessels in theanalyzer to perform tests with the analyzer, updating reagent filllevels associated with the reagent vessels from which reagents aretransferred in the step of transferring, and updating the graphicalelements with new ones of the graphical fill level representations toreflect the updated fill levels as reagents are transferred from thevessels to perform tests with the analyzer.
 59. The method of claim 58wherein the step of displaying a pictorial representation is performedas part of displaying a combined worklist screen in the step ofresponding to user actuation of a worklist icon.
 60. The method of claim58 wherein the step of displaying a pictorial representation employsgraphical elements that are shaped like the vessels provided in the stepof providing a plurality of different reagent vessels that each storeone or more different reagents for use by the analyzer.
 61. The methodof claim 60 wherein the graphical fill level representations that coverdifferent amounts of area are each shaded areas in the vessel-shapedgraphical elements.
 62. The method of claim 58 further including thestep of identifying the contents of a plurality of vessels that storesamples for use by the analyzer, and the step of displaying to theoperator a pictorial representation that includes a plurality ofelements that identify the contents of the vessels.
 63. The method ofclaim 62 wherein the pictorial representation of the reagent vessels andthe sample vessels are part of a combined representation.
 64. The methodof claim 62 wherein the step of displaying the worklist icon displays afirst pictorial representation in the worklist icon, wherein the step ofdisplaying the status icon displays a second pictorial representation inthe status icon, wherein the step of displaying the results icondisplays a third pictorial representation in the results icon, whereinthe step of displaying the diagnostics, maintenance, and/or set up icondisplays a fourth pictorial representation in the diagnostics,maintenance, and/or set up icon, wherein the first, second, third, andfourth icons are all different.
 65. The method of claim 58 wherein thepictorial representation is a mapped pictorial representation in whichpositions of the graphical elements on the display correspond topositions of the vessels in the analyzer.
 66. The method of claim 65wherein the step of displaying a pictorial representation employsgraphical elements that are shaped like the vessels provided in the stepof providing a plurality of different reagent vessels that each storeone or more different reagents for use by the analyzer.
 67. The methodof claim 66 wherein the graphical fill level representations that coverdifferent amounts of area are each shaded areas in the vessel-shapedgraphical elements.
 68. The method of claim 58 wherein the pictorialrepresentation employs colored bars having different areas to convey thefill levels.
 69. The method of claim 58 wherein the pictorialrepresentation includes elements that identify the reagents in thereagent vessels.
 70. The method of claim 57 wherein the step ofdisplaying the worklist icon displays a first pictorial representationin the worklist icon, wherein the step of displaying the status icondisplays a second pictorial representation in the status icon, whereinthe step of displaying the results icon displays a third pictorialrepresentation in the results icon, wherein the step of displaying thediagnostics, maintenance, and/or set up icon displays a fourth pictorialrepresentation in the diagnostics, maintenance, and/or set up icon,wherein the first, second, third, and fourth icons are all different.71. A chemistry analyzer, including: a reagent/sample carouselsubassembly for holding a plurality of sample vials for samples ofdifferent patients and for holding a plurality reagent vessels that eachstore one or more different reagents for testing different selectedanalytes in blood, a reaction carousel subassembly that defines cuvettelocations, a transfer arm subassembly including a probe for transferringreagents and samples to the cuvette locations, a probe wash stationpositioned along an arc of motion of the transfer arm, and a photometerpositioned to acquire photometric measurements from the cuvettelocations in the reaction carousel, a touch screen, a programmedcomputer operatively connected to the touch screen and including storedsoftware operative to simultaneously display on the touch screen adisplay area and series of four access icons including a worklist icon,a results icon, a status icon, and a diagnostics, maintenance, and/orset up icon, which are each associated with a different color and eachallow access to information for different types of operations for theanalyzer, wherein the information is color coded to correspond to thecolor associated with their respective access icons, wherein theprogrammed computer is responsive to user actuation on the touch screenof the worklist icon that is associated with a first color to display aworklist menu while continuing to display the four access icons on thetouch screen, and wherein the worklist menu is responsive to a userselection in the worklist menu to display one of a plurality ofsub-screens that is color coded according to the first color in thedisplay area, including a data table sub-screen that lists tests for theanalyzer, while continuing to display the four access icons on the touchscreen, wherein the programmed computer is responsive to user actuationon the touch screen of the status icon that is associated with a secondcolor to display a status menu while continuing to display the fouraccess icons on the touch screen, and wherein the status menu isresponsive to a user selection in the status menu to display one of aplurality of sub-screens that is color coded according to the secondcolor, including a status sub-screen that lists a plurality of statusentries, while continuing to display the four access icons on the touchscreen, wherein the programmed computer is responsive to user actuationon the touch screen of the results icon that is associated with a thirdcolor to display a results menu while continuing to display the fouraccess icons on the touch screen, and where in the results menu isresponsive to a user selection and the results menu to display one ofthe plurality of sub-screens that is color coded according to the thirdcolor, including a results sub-screen that lists a plurality of resultsentries, while continuing to display the four access icons on the touchscreen, and wherein the programmed computer is responsive to useractuation on the touch screen of the diagnostics, maintenance, and/orsetup icon that is associated with a fourth color to display adiagnostics, maintenance, and/or setup menu while continuing to displaythe four access icons on the touch screen, and wherein the diagnostics,maintenance, and/or setup menu is responsive to user selection in thediagnostics, maintenance, and/or setup menu to display one of aplurality of sub-screens that is color coded according to the fourthcolor, including a diagnostics, maintenance, and/or setup icon entrysub-subscreen, while continuing to display the four access icons on thetouch screen.
 72. The apparatus of claim 71 wherein the programmedcomputer is operative to display a first pictorial representation in theworklist icon, wherein the programmed computer is operative to display asecond pictorial representation in the status icon, wherein theprogrammed computer is operative to display a third pictorialrepresentation in the results icon, wherein the programmed computer isoperative to display a fourth pictorial representation in thediagnostics, maintenance, and/or set up icon, wherein the first, second,third, and fourth icons are all different.